Quantum computers need vastly fewer resources than thought to break vital encryption

Quantum computers now require far fewer resources than previously estimated to break RSA encryption, compressing the timeline for digital security obsolescence. A 2026 study by researchers at MIT and the University of Waterloo found that a theoretical quantum machine needs only 1,200 logical qubits to crack a 4,096-bit RSA key—down from earlier estimates of 20 million. This is 30% lighter than the runner-up algorithm's resource demands, making the threat more immediate than the average prior projection. The finding challenges the longstanding assumption that quantum decryption remained decades away, with experts now urging accelerated post-quantum cryptography adoption.